9PGH
The cryo-EM structure of C. crescentus RNAP-Sigma73-CCNA_03891/CCNA_01149 promoter complex
Summary for 9PGH
| Entry DOI | 10.2210/pdb9pgh/pdb |
| EMDB information | 71632 |
| Descriptor | DNA-directed RNA polymerase subunit alpha, DNA-directed RNA polymerase subunit beta, DNA-directed RNA polymerase subunit beta', ... (9 entities in total) |
| Functional Keywords | ccna_03891-ccna_01149 promoter complex, drid, caulobacter, rna polymerase, transcription, transcription-dna complex, transcription/dna |
| Biological source | Caulobacter vibrioides NA1000 More |
| Total number of polymer chains | 8 |
| Total formula weight | 527489.72 |
| Authors | Singh, R.R.,Schumacher, M.A. (deposition date: 2025-07-07, release date: 2026-02-25, Last modification date: 2026-04-15) |
| Primary citation | Singh, R.R.,Chinni, A.,Cannistraci, E.,Salinas, R.,Yadav, S.,Gozzi, K.,Schumacher, M.A. Transcription activation mechanism of a noncanonical DNA damage response pathway by the WYL-activator, DriD. Sci Adv, 12:eaec6337-eaec6337, 2026 Cited by PubMed Abstract: DNA damage repair mechanisms are vital for cell survival. In the bacterium, , DriD is the master regulator of a unique, noncanonical DNA damage pathway. DriD binding to ssDNA, produced upon DNA damage, stimulates its ability to activate transcription from several promoters involved in DNA damage responses. However, the mechanism by which DriD interfaces with the RNAP holoenzyme to activate transcription from its multiple promoters has been unclear. Here, we describe cryo-EM structures of DriD-ssDNA bound to RNAP-holoenzyme and three DriD-regulated promoters. Each subunit of homodimeric DriD contains an DNA binding -terminal winged helix-turn-helix (wHTH) connected to WYL domains by a linker 3-helix bundle (3HB) module. The structures reveal a mechanism of assembly on promoters whereby DriD's 3HBs bind the RNAP α-CTD and β domains, anchoring the RNAP-holoenzyme to regulated promoters. The 3HBs form autoinhibitory contacts with DNABDs in apo DriD and therefore acts as an ssDNA-driven trigger domain, switching between DNABD-bound apo and RNAP-bound forms upon ssDNA-mediated activation. Thus, the structures reveal a unique transcription activation mechanism, likely conserved among the large family of homodimeric WYL activators. PubMed: 41861017DOI: 10.1126/sciadv.aec6337 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.54 Å) |
Structure validation
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